This Phase I STTR proposal seeks funding to support development and evaluation of a prototype low-cost, easy to use and portable ultrasound imaging system. There are many applications in clinical medicine where such a transcutaneous imaging system would be of great value. For this proposal, our main focus is to provide guidance for intravenous catheter insertion. The role of ultrasound in this and other similar needle insertion procedures is well known. However, this research is oriented towards achieving an order of magnitude cost reduction, retaining reasonable image quality (particularly contrast), and developing the versatility to offer additional scan planes beyond those currently in common practice. Specifically, the proposed system will provide C-Scan capability using a highly integrated 2D transducer array and beamformer. We hypothesize that C-scan imaging will make our system considerably more intuitive to the less experienced user and therefore more likely to be widely accepted. The Aims of this proposal are: 1). Assemble C-scan imaging system consisting of 2D array, existing custom integrated circuit and PC-based beamformer. This prototype will provide proof of concept for this low cost imaging strategy and builds from previous research in 2D transducer technology, novel beamforming algorithms and highly integrated circuitry. 2.) Obtain phantom data using prototype system and compare beamforming algorithms off-line. Using the prototype, experimental data will be gathered in order to test system performance with several new beamforming strategies. 3.) Design, fabricate, and test high-risk aspects of the integrated circuit and associated packaging. Performance aspects of the integrated circuit such as SNR, power, crosstalk, protection circuits and transducer interface will be tested with the production of a prototype board. These aims will test the hypothesis that a combination of integrated circuit topology, low profile 2D array, and beamforming algorithms can be implemented in order to meet the cost, size, and power constraints of our long-term goals. This research is a collaborative effort between PocketSonics and the University of Virginia Departments of Biomedical Engineering and Electrical and Computer Engineering.